Trapania Sanctipetrensis is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.

[2] This species was described from Sancti-Petri, Chiclana de la Frontera, Bay of Cadiz, south west Spain.

[3] The body of the Trapania Sanctipetrensis is translucent white with a network of brown markings on the surface.

The gills, oral tentacles and tail are tipped with white pigment.

[4] Trapania sanctipetrensis probably feeds on Entoprocta which often grow on sponges and other living substrata but it was found on Bugula neritina.